However, one particularity of the human species is that pair bonds are often formed without necessarily having the intention of reproduction.
In modern times, emphasis on the institution of marriage, generally described as a male-female bond, has obscured pair bonds formed by same-sex and transsexual couples, and that many heterosexual couples also bond for life without offspring, or that often pairs that do have offspring separate.
As humans societies have evolved from hunter-gatherers into civilized societies, there have been substantial changes in relations between men and women, with perhaps one of a few remaining biological constants being that both adult women and men must have sexual intercourse for human procreation to happen.
Humans have been compared to other species in terms of sexual behavior.
From about 1700 a worldwide movement perhaps described as the "empowerment of the individual" took hold, leading towards greater emancipation of women and equality of individuals.
Men and women became more equal politically, financially, and socially in many nations.
Accordingly, there was little need for a temporary trial period such as dating before a permanent community-recognized union was formed between a man and a woman.
While pair-bonds of varying forms were recognized by most societies as acceptable social arrangements, marriage was reserved for heterosexual pairings and had a transactional nature, where wives were in many cases a form of property being exchanged between father and husband, and who would have to serve the function of reproduction.
Today, the institution of dating continues to evolve at a rapid rate with new possibilities and choices opening up particularly through online dating.
Social rules regarding dating vary considerably according to variables such as country, social class, race, religion, age, sexual orientation and gender.
Thus, the concept of marriage is changing widely in many countries.
Historically, marriages in most societies were arranged by parents and older relatives with the goal not being love but legacy and "economic stability and political alliances", according to anthropologists.
The protocols and practices of dating, and the terms used to describe it, vary considerably from country to country and over time.